The present invention relates to a method for dressing a material comprising noble metals and platinum group metals, respectively, as well as impurities, and means for performing said method.
In practice, materials come to hand which have a total content of gold, platinum, palladium, rhodium, and iridium of 20% or more. Such materials mostly contain impurities being accompanying metals of said elements and/or other elements, which form volatile compounds and compounds of chlorine, respectively, with oxygen, hydrogen and chlorine. Materials of this kind may be residues from other processes, mixtures or alloys.
It is an object of the present invention to provide a method for dressing said materials in such a way that a concentrated residue of gold, platinum, palladium, rhodium and/or iridium is left, this dressing being done as economically and environmentally safe as possible.
In the method of the above kind, for dressing a material comprising noble metals including platinum group metals, as well as undesired materials comprises subjecting the materials to an oxidizing treatment at a temperature within a first temperature range. The material is then subsequently subjected to a reducing treatment at a temperature within a second temperature range. Finally, the material is chlorinated at a temperature within a third temperature range.
Another object of the present invention is providing means for performing said method.
According to the present invention, a device for performing a method for dressing a material comprising noble metals, including platinum group metals, as well as impurities, comprises a reactor vessel that includes an inlet for a treatment medium for the material. The inlet is located in the lower region of the reactor vessel. The vessel also includes an outlet for the treatment medium that is located in an upper region of the reactor vessel. The reactor vessel also includes a device for distributing a stream of the treatment medium that is arranged inside the reactor vessel.